There’s no movie blather like journalism movie blather. Even if you’re not a journalist, you can usually tell when a fact-based biopic about investigative reporters or a war correspondent settles for shortcuts, speech-y overstatement and, yes, fake news.

The new film “A Private War” ranks higher than most in the truth department and in cinematic storytelling. Whatever your personal interest or disinterest in Sunday Times reporter Marie Colvin’s line of work, the way she did it — and the bloody global conflicts she ran toward, full gallop — makes for a tense, engrossing account. She was killed in Syria in 2012 while covering the Assad regime’s slaughter of its own people.

Rosamund Pike, best known in the U.S. as the heartless heart of “Gone Girl,” portrays Colvin, but the casting isn’t ideal. The actress carries trace elements of royalty with her everywhere she goes. Yet this is her best work on the screen outside British period pieces. Documentary-trained director Matthew Heineman’s narrative feature debut leans into the mess and complication of Colvin’s life and away, thank God, from sainthood.

The movie is based on the 2012 Vanity Fair feature “Marie Colvin’s Private War” by Marie Brenner, though screenwriter Arash Amel pulls from other sources. More or less chronologically Amel follows the last 11 years in the life of the Long Island-raised London transplant from the Sri Lanka civil war assignment that cost her a left eye (she wore a patch thereafter) to the U.S.-led Iraq invasion to Libya (she was propositioned, relentlessly, by Moammar Gadhafi) to Afghanistan and finally, fatefully, to Syria. Photographer Paul Conroy worked and traveled with Colvin through much of this, and Jamie Dornan (“Fifty Shades of Grey”) plays him as a loyal colleague perpetually at risk.

“A Private War” doesn’t invent much, though the script eliminates a marriage here, a resume item there. Pike’s unblinking, emphatic quality has its limitations, but by the film’s midpoint, she rolls with every scene. Fierce and alert, she holds the screen. Heineman made a shrewd decision not to ennoble this woman, or lard “A Private War” with starry close-ups. It’s about an on-the-ground reporter who, in her words, simply wanted to make the casualties of war “part of the record.” Showing us what that meant is enough.